Acer H6517ST
Full HD, 3000 lm, 0.5:1
Acer H6517ST
Full HD, 3000 lm, 0.5:1
The unit has a fixed projection ratio of 0.5:1. (This is common for short distance/ultra short distance projectors.) This means that the image size can only be changed by moving the unit further backwards or forwards. The unit then has a focus control with which the image can then be brought into focus at the appropriate distance. - Formula: Projection distance = screen width /(by) projection ratio.